This is a rechargeable self-skin checker. Please check the 4th image for the shape of the charging port. There are no instructions. How to use: 1. Long press the power button on the right to turn it on. 2. Press the ◻︎ button next to the power button. 3. Hold it on the area you want to diagnose for about 3 seconds (it will beep three times). 4. When it beeps, the diagnosis result will be displayed. Please refer to the 6th image for the numerical values. Please understand that this is stored by an amateur. Immediate purchase is welcome◎!